Noise pollution would be reduced.

Military Air Shows can be dangerous to participants and spectators.

The money could be better spent on public services

Burning less fossil fuels would reduce carbon emissions

It promotes war and conflict which have significant negative ramifications for those caught in the middle.

The jets are a traumatic reminder (and sometimes triggers for PTSD) for those who've fled conflict zones

The demonstration of a strong military makes citizens feel safer and other countries less likely to attack your country.

Military air shows are popular and entertaining for the public.

They inspire people to be interested in STEM fields.

Military air shows are some of the few opportunities where pilots get to fly the actual airplane rather than the simulator, and get to gain experience which is needed in case of an emergency so they can better respond with more skill and knowledge about flying the airplane.

They are a way for pilots to demonstrate their skills and the capacity of the jets!

They inspire national pride for those who are pro-militarisation and connect ornaments with a countries power (and ability to defend itself)